Accelerator for the vulcanization of rubber



Patented July 5,.i927.

UNITED STATES 1,634,925 PATENT OFFICE.

GEORGE STAFFORD WHITBY, or 1 MONTREAL, QUEBEC, CANADA, ASSIGNOR 'ro THE ROESSLER & HASSLACHER CHEMICAL Co., or NEW YORK, N. Y., A ConroRA'rIouor NEW YORK.

ACCELERATOR FOR'LHE VULGANIZATION F RUBBER.

No Drawing. Application filed January The object of'this invention is to provide a new and improved class of accelerators for the vulcanization of rubber which will give to the finished rubber product excellent physical properties such as desirable stress strain relationship, high tensile strength, rapidity of vulcanization and related properties.

This invention relates to the use'of compounds which are formed by the reaction 1 of salts of dithiocarbamic acids with sulphur chlorides. These reaction products are new in the art; the preparation of these is disclosed in a copending application, S. N. 84,153, filed by me of even date herewith 1 and the new compositioiis of matter are claimed therein.

I have found that if thesecompounds are used as accelerators in the vulcanization of rubber very superior results are obtained as 2 shown in the examples .given below.

27, 1926. Serial No. 84,154.

As shown in my copending application, S. N. 84,153, the'compounds are formed from dithiocarbainates of the general formula:

wherein B may be hydrogen or any organic radical while R is hydrogen o en organic radical similar or dissimilar to R; M may be any metallic element or equivalent group Thus, forexample, if sulphur nionochloride is used the general reaction becomes:

whereas if sulphur dichloride is used a t risulphide form results viz:

40 The chloride of the metal M is always formed in the reaction. The arrangement of the central sulphur atoms represented as SK, or S is unknown to me. Theseproducts'are simply named as substituted thiuram polysulpliideasuch as, tetra substituted thiuram tetra sulphide or trisulphide.

I have prepared and used as accelerators of vulcanization new materials prepared from sulphur monochloride and sulphur di- Chloride with various salts of dimethyl-, di-

dibutyl-, ,dipropyL, piperidyl-,

phenylmeth 1- and phen l ethyl-'dithiocarbamic aci I have used ethy1-',

zinc, potassium, sodium and ammonium salts of these in various combinations.

The thiuram polysulphides thus formed may be used as the accelerator in any common' rubber compound which utilizes as a .basic-pmixturetheingredients rubber or similar material and sulphur; this basic mixture may be utilized in a great variety ofcompounds, such as those for example utilizing.

o ExAMPLE I. ,De-pipefidyl tkz'umm tetrasulphz'de.

100 parts by weight of smoked sheet, 5 parts by wei ht of zinc oxide, 5 parts-by weight of sulphur, 0.5 parts by weight of product above named. i

This mixture was properly milled and carbon'black and other coloring v then cured at a temperature corresponding to that ofosteam at 10 lbs/in following results were obtained Dal-phenylethyl thz'umm tetmeulphz'de.

100 parts by wei ht smoked sheet, 5 parts by weight Zinc oxi e, 5 parts by weight sulphur, 0.5 part by weight of above named compound.

This mixture was suitably milled and then cured at a temperature corresponding to that of steam at 10 lbs/in pressure. The results were:

Time of cure. Stretch. 2 3: Tensile strength.

30 minutes. a. s 2000 lbs/in 4581 lhs/im 40 minutes. 8. Q1 2500lbS./i!1 4903 lbSJiH 50 minutes. 8. 6 2000 lbS./i!1 39901135.,1'1

EXAMPLE III. Di-phenylethyl thin-mm tctrasulphz'cl'e.

100 parts by weight smoked sheet, 5 parts by weight zinc oxide, 4 parts by weight of above named compound.

Cured at temperature corresponding to that of steam at 10 lbs/in pressure.

f Time of cure. Stretch. Tensile strength.

3059 lbs/in 45 minutes 3704 lbs/in 7. 9 60 minutes 8. 0

'EXAMPLE IV.

Di-plzenylethyl thiumm tetrasulplzde accelemtor.

pressure. The 10 pounds steam.

Di phenje/letkyl thiumm trz'suZp/zida- 0.5 parts by ,weight of this were used as accelerator in the formula of example V. Cured at a temperature of 10 pounds steam.

the accelerator V. Cured attem Tetra-methyl th'iut'am 'trz'sulphide.

0.5 parts by weight of this were used as in the formula of example perature of 10 pound steam.

Time of cure. Stretch. g g Tensile strength.

30 minutes. 9. U 17001bS./in* 4361lbs./in 4 40 m nutes. 8. 5 2200Ibs./in' 4613 lbs/in 50 minutes. 8.0 33001bs./in 4468 lbs/in EXAMPLE VIII. Tetra-butg l thiuo'am tet'rasulphz'de.

0.5 parts by weight of this were used as the accelerator in the formula of Example V. Cured at temperatur e 0f 10 lbs. steam.

0 Time of cure. Stretch. g g Tensile strength.

i 30 minutes. 9. 5 000 lbs/in 3658 lbs/in 40 minutes. 9. 0 1500 lbs/in -1393lh:l./in 50 minutes. 8.5 2600 lbs/1n 4361 lbs/in 60 minutes. 8. 12 2500 lbs/1n 4035 lbs/in EXAMPLE IX.

' atm".

Tetra-methyl t/zi'u'mm) fl ti'asitZp/zide acceler- 100 parts by weight smoked sheet,.5 parts by weight zinc oxide,

I 5 parts by weight (10 Time oicura. Stretch. g gfig Tensile strength. celerator' Cured at a temperature of 10 pound 45 minutes. 8.1 2800lbs./in enema/m steam $2$" 2- assear-e:

nu i Time of cure. Stretch. gggg q Tel-wile strength.

EXAMPLE V. I 15 minutes. a. 02 14501bs./in' 80901bs./in Tetmethryl thcwmm tetrasulphzde acceterminimum. 8.6 Bombs/in mam/inat 30minutes. as l450lba./m 3749lbu./in"

100 parts by weight smoked sheet, '5 parts by weight zinc oxide, 5 parts by weight I sulphur, 0.5 parts by weight accelerator.

It will be noted that Examples III and X illustrate an application of my inventlon wherein no free sulphur is compounded with the rubber; the elysul hide carries" with it-the requisite sulphur.

The above examples are merely for purposes of. illustration of methods ofpracticmaterial which comprises. incorporating ing my invention and I do not desire to be limited to the ingredients-of the rubber mix tures noted nor to any the proportions and methods given since my accelerators are capable of wide adaptation in rubber mixes.

.What I claim is:

1. A process of treating rubber or similar I with the rubber compound a vulcanizing material which g material materialL which. comprises agent and a thiuram polysulphide containing more than four atoms of sulphur per molecule; and vulcanizing.

a 2. A process of treating rubber or similar comprises incorporating with the rubber compound a vulcanizing agent and a substituted thiuram polysulp ide containing more than four atoms or I sulphur per molecule. and vulcanizing.

3. A process of treating rubber. or similar which comprises incorporating with the crubber compound a vulcanizig agent and a diaryl-dialkyl substitlififi thiuram polysulphide containing more than four atoms of sulphur per molecule, and vulcanizing. 4. A process of treating rubber or similar material which comprises incorporating with the rubber a tetrasubstituted thiuram polysulphide containing more than four atoms of sulphur per molecule and yulcan'iz g A process of treating rubber or similar material which comprises incorporating with-the rubber a vulcanizing agent and the reaction product of a substituted dithiocarbamate with a sulphur chloride of the formula S Cl and vulcanizing.

6. A process of treating rubber or similar incorporating material which comprises -with the rubber a.

vulcanizing agent and the reaction product of a disubstituted'dithiocarbamate with a sulphur chloride of the formula S Cl and vulcanizing.

' rubber or similar incorporating a vulcanizing agent and a 7 A process of treating with the rubber thiuram polysulphide of the general for- While, R is hydrogen with the rubber wherein R is hydrogen or an organic radical or an organic radical similar 'oridissimilar to R, and vulcanizing. .8. A process of treating rubber or'similar material which a vulcanizing agent and a thiuram polysulphide of the general fororganic radicals, and

withthe rubber a thiuram polysulphide of the general forcomprises incorporating wherein R and R aresimilaror; dissimilar vulcanizing. I

'9; A process of treating rubber or similar material whic comprises incorporating vulcanizing. agent and a wherein R is hydrogen or an organic radical while R 1S hydrogen or an organic radical similar or dissimilar to R, and vulcanizing. j

10. The process of accelerating the vulcanization of rubbencomprising vulcanizing the same in the presence of atliiuram polysulfide containing more than four atoms of sulfur per molecule.

11. The process of accelerating the-.v'ulcaniz'ation of rubber comprising vulcanizing the same in the presence of a diaryl-dialkyl substituted 'thiuram polysulfide containing more than .four' atoms of sulfur per molecule. 12. The process of accelerating the vulcanization of rubber comprising vulcanizing the same in the presence of the reaction product of a dithiocarbamate with a sulfur chloride of the formula S CI 13. The process of accelerating the vul-. canization of rubber comprising vulcanizing the same-in the presence of the reaction product of a substituted dithiocarbamate with a sulfur chloride of. the formula 8 01 1 14. The process of accelerating the vul-f canization of rubber comprising vulcanizing i the same in thepresence of a thiuram polylsulfide of the general formula wherein R is hydrogen or an organic radical while R is hydrogenor an organic radi I cal similar or dissimilar toR.

17 The process of accelerating the vul'-' caniza'tionj of rubber comprising vulcanizin the same in the presence of athiuram po lysulfide of the general formula.

whereinvR andR -are similar or dissimilar organic radicals. a 18. The process of accelerating the vulthe same in the presence of a thin'ram polysulfide of the general formula -Wherein R is hydrogen or an organic radical while R is hydrogen or an organic radical similar or dissimilar to R.

19. The process of accelerating the vulcanization of rubber comprising vulcanizing the same in the presence of uram tetrasulfide.

20. A vulcanized rubber derived from rubher or similar material in which is incorporated a vulcanizing agent and a substituted thiuram polysulpbide containing more than four atoms of sulphur per molecule.

21. A vulcanized rubber derived from rubber or similar material in which is incorporated .a thiuram more than four atoms of sulphur per molecule.

22. A vulcanized rubber derived from rubher or similar material in which is incorporated tetra substituted thiuram polysulphide containing more than four atoms of sulphur per molecule.

23. A vulcanized rubber derived from rubber or similar material in which is incorporated a vulcanizing agent and the reaction product of a dithiocarbamate with a sulphur chloride of the formula S GF.

24. A vulcanized rubber derived from rubher or similar material in which incorpo* rated a vulcanizing agent and the reaction d iphen 'lethyl thiproduct of a substituted dithiocarbaniate with a sulphur chloride of the formula S CI 25. A vulcanized rubber derived from rubber or similar material in which is incorporated a vulcanizing agent and the reaction product of a disubstituted dithiocarbamate with sulphur monochloride. l

26. A vulcanized rubber derived from rubber or similar material combined with a vulcanizing agent and diphenylethyl thiuram tetrasulpliide.

27. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with addition thereto of an orfl'tlIllC pol sulfide of the general formula TRRNC S where R and R represent olvsul hide containin hydrocarbon radicals and a: a number greater than 2. j 28. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with the addition thereto of an organic (R-. .-N.CS) S where R represents alkyl.

29. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with the addition thereto of an organic polysulfide of the general formula (Et N.CS) S 30. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with the addition thereto of an organic polysulfide oi the general formula (Me NCS) s,

31. The method of vulcanizing rubber without the addition of sulfur, which romprises subjecting the rubber to vulcanization with an organic polysultide of the general formula (RRN.CS). .S (where m is a number greater than 2 and R and R represent hydrocarbon radichls) as the vulcaniziug agent.

32. The method of vulcanizing rubber without the addition'of sulfur which coinprises subjecting the rubber to vulcanization with tetrametliylthiuran'ipolysnlfide as the vulcanizing agent.

33. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with the addition of sulfur.

and an organic polysulfide of the general formula (RR'N.CS) S (where a; is a number greater than 2 and R and R- represent hydrocarbon radicals) as an accelerator.

34. The method of vulcanizing rubber which comprises subjecting the rubber to vulcanization with the addition of sulfur, with tetramethylthiurampolysultide as the acceler- Y ator.

with tetraethylthiurampolysullide as the accelerator.

Signed at Perth Amboy in.the' county of Middlesex and State of New Jersey this 16th day of January A. D. 1926.

. GEORGE STAFFORD WHIIRY.

polysulfide of the general formula 

